Astro-G, KVN/VERA(EAVN), VLBA, ALMA の現状と今後

H.Kobayashi(NAOJ)2011, Sep.,27

多波長で探る AGN ジェット研究会

Target Life Time is 3 years.

Dual pol. @ 8, 22, 43 GHz Phase-referencing capability Switching Maneuver 10 cm Orbit Determination

9.3 m Antenna with high surface accuracy (0.4mm rms)precision pointing (0.005deg)

1 Gbps Data Downlink

ASTRO-G Mission

Cancellation of Astro-G

2009.3-7 PDR• Uncertainty of deployment antenna repeatability• Problems of surface accuracy (thermal conditions,

radiation conditions) 2009.7-2010.8 Tiger team activity

• Only 1mm rms is achievable.• Cost will overrun more than 50% of initial cost.

2010.9 ISAS Science council recommended the cancellation.

2010.12 ISAS advisory council also recommended it. 2011.09 宇宙開発委員会での結論

East Asian VLBI Network array

Current working VLBI stations in Eastern Asia

Japan(13)• VERA(4), Kashima, Tsukuba, Yamaguchi,

Nobeyama, Usuda, Tomakomai, 　 Gifu, 　Uchinoura, Takahagi, Hitachi

Korea(3)• KVN (3) Yonsei, Ulsan, Tamna

China(4)• Shanghai, Urumqi, Beijin, Kumming• Shanghai 65m 　

Feature of East Asia VLBI network

Largest number of VLBI stations• 8GHz 13 stations• 22GHz 19 stations• 43GHz 8 stations• S/X geodesy 13 stations

Phase referencing• VERA 2 beam system• KVN multi-frequency + fast nodding

Good UV coverage• Minimum baseline length ; 50 km• Maximum baseline length ; 5000 km

Observation features

Phase referencing observations• VERA 2 beam• KVN multi-frequency• Nodding -> high sensitivity observations for low Tb objects

(RQQ, SNR, Galactic objects) ->astrometry for maser sources (H2O,SiO,CH3OH..)

High dynamic range observations

Ground array of VSOP-2

Total effective aperture and baseline length

VLBI array EAVN VLBA EVN

No. of Stations

２０ １０ １２

Baseline length

5,000km 8,000km 2,000km-8,000km

Effective Aperture ８GH ｚ

9,000m2 3,700m2 9,800m2

Effective Aperture 22GHz

4,900m2 3,200m2 4,900m2

Effective 　Aperture 43GHz

1,400m2 2,900m2 1,800m2

Current status of astrometry with VERA

Japanese VLBI Network (JVN) Collaboration

• NAOJ (VERA)• Hokkaido, Ibaraki, Tsukuba,

Gifu, Osaka-Pref, Yamaguchi, Kagoshima university

• JAXA, NICT, GSI• 13 telescopes (11m ~ 64m)

Purpose• A new, characteristic VLBI

array• A Base of East-Asian VLBI

Progress• Started in 2004• Steady Observation in 2005• First Paper published in 2006

Observing time ~200 hr/yr

• EAVN test observation

Simultaneous Multi-Frequency Obs. -Phase Compensation, mm-VLBI

Constructions of three stations were completed on Dec. 2008 !

Freq. Band S Band X Band K Band Q Band

Freq. Range 2.2 ~ 2.8 GHz 8 ~ 9 GHz 21.5 ~23.5 GHz 42 ~ 44 GHz

Rx Noise < 25 K < 25 K < 30 K < 50 K

1st IF / BW 2.5G/600MHz 8.5G/1GHz 8.5G/2GHz 8.5G/2GHz

IF Power -20 dBm -20 dBm -20 dBm -20 dBm

Polarization LCP/RCP LCP/RCP LCP/RCP LCP/RCP

* 86, 129 GHz Receivers will be installed.

Prototype 43 GHz Re-ceiver

Receiver

Seoul VLBI correlator center

Opened on May 13th, 2010

8Gbps x 16 station 　　 Largest VLBI correlator

VERA/Tape

terminal

Korea/China

(Mark-5b)

VERA/Disk

(VOA)

Optical fiber

(VSI-E)

ＶＬＢＩ data server

Wideband correlator

8Gbps

16 stations Data processing and archive

Operation System

New Correlator at Seoul - Joint development with Korea and Japan –

Software correlator

1Gbpsx4 stations

Schedule

２０１０　　• Test Observations with VERA+KVN

2011• Start of science observations with Japan

(VERA,JVN) /Korea (KVN), and Japan(JVN)/China(CVN).

2012• Start of science observations with Japan,

Korea and China

Atacama Large Millimeter/submillimeter ArrayExpanded Very Large Array

Robert C. Byrd Green Bank TelescopeVery Long Baseline Array

VLBA Operational StatusOngoing and Possible Future Upgrades

Walter BriskenNRAO, Socorro

Current capabilities of the VLBA 45 baselines from 10 identical 25m antennas Peak / sustainable record rate is 512 Mbps

• 64 MHz/polarization with 2-bit samples Operates at select bands between 330 MHz and

90 GHz• Dual band 2.2 / 8.4 GHz supported

1-hour continuum sensitivity at 8.4 GHz = 54 Jy RMS

Angular resolution at 8.4 GHz is 1x2 mas

18

Current capabilities of the VLBA

Absolute astrometry to a precision of 100 as Relative astrometry to a precision of 10 as Flexible correlation with DiFX

• Can correlate at ~700 Mbps x 10 antennas for typical projects

• 16 playback Mark5 units available• Transient processor

VLBA Sensitivity Upgrade Project(http://www.vlba.nrao.edu/memos/sensi/)

Began as a project in 2007 Three major components of the upgrade are:

• New correlator DiFX software correlator was ultimately chosen

• New data recorder Mark5C, developed by Haystack/Conduant/NRAO

• New antenna back-end electronics ROACH FPGA-based Digital Back End (RDBE) in

development Project funded (including media) to complete 2 Gbps

capability• Funding from NRAO, NSF MRI grant and Conacyt (via

UNAM)• Initial availability to astronomers anticipated this

summer 20Goal: increase peak bandwidth to 4 Gbps

VLBA 　運用継続問題 NSF ：　 VLBA 運用経費（６ M$/yr) 半分以上を

non-NSF fund で運用しないと 2011 年 10 月からBudget cut

2011 年 2 月　 VLBA future WS• サポートの目標 (3M$/yr)

NRAO 1M$/yr 自助努力 ○ Naval Obs. 1M$/yr -> daily UT1 決定　○ FERMI 　　　　　 0.15 M$/yr 　 Shanghai 0.2 M$/yr 　　○ ASISS 0.2 M$/yr 　　○ MPIfRA 0.2 M$/yr 　　申請中 CSIRO/ICRUR 0.15 M$/yr NAOJ 0.2 M$/yr

VLBI 長期計画の必要性 国内問題

• Astro-G の中止 次期スペース VLBI を提案するのか、しないか？ AGN などの研究をどのように発展させるのか？

国際的な VLBI ロードマップの必要性• 多波長や電波の他分野に対する VLBI の存在意義の明確化

ALMA 、 SKA との関係 VLBI 　 Large program の戦略

• Global array 構想の浮上 VLBA の運用スキームの変更

東アジア VLBI 観測網の開始• VLBA/EVN などとの棲み分け

位相補償・高い周波数・・・・

長期計画の策定について 研究目的を明確にする

• 研究目標の設定　• 実現性（装置性能・マンパワー）の検討

開発計画を明確にする• 周波数バンド• 記録帯域• eVLBI

予算計画

来年の EAVN シンポに向けて Need considerations by each countries and

groups• White papers of research subjects (What do we

want?)• Development schedule (What can we do?)• Realistic operation plan (How much can we do?)

Need to start activities of Road map creation• Science goal• Development scope• Operation scheme

ALMA project

15th of August: 18 antennas at the AOS

ＡＬＭＡ　Ｃｙｃｌｅ - ０　time allocation

ALMA Schedule

2011 　 Sep. 　　 Start of Early Science

2013 Mar. 開所式 2014 　 Jan. 　　　 66 台フル運用 Antenna

• 2012 　 2nd Quarter : EA 16 台完• 2013 　 1st 　 Quarter 　：　 NA 　 25 台完• 2013 　 3rd Quarter : EU 25 台完